The combination of non-contrast abbreviated MRI and alpha foetoprotein has high performance for hepatocellular carcinoma screening

Hepatocellular Carcinoma Screening: From Current Standard of Care to Future Directions

Hepatocellular carcinoma (HCC) represents a significant portion of global cancer incidence and mortality. Screening with ultrasound with or without alpha-fetoprotein is recommended for those at high-risk. Although screening can lead to earlier treatment and better outcomes, existing screening paradigms have several flaws. Ultrasound does not capture all early lesions and has lower efficacy in specific populations such as patients with obesity or those with metabolic dysfunction-associated steatotic liver disease (MASLD). Additionally, individuals with noncirrhotic MASLD and chronic hepatitis C also develop HCC, although not at high enough rates to justify screening based on current standards. These individuals, however, represent a substantial proportion of new HCC cases given rising MASLD rates and the endemic nature of hepatitis C in certain regions. Risk-stratifying these populations may reveal subsets that are higher risk and warrant screening. Several imaging advances, including contrast-enhanced ultrasound and abbreviated MRI protocols, may improve detection compared with the current approach. Evaluation of risk stratification and validation of these new imaging methods via clinical trials would likely lead to adjusting screening guidelines. This narrative review provides a diagnostic and interventional radiology-focused summary of the HCC screening guidelines and their recent evolution and highlights emerging imaging methods as potential screening tools of the future.

Hepatocellular Carcinoma: Imaging Advances in 2024 with a Focus on Magnetic Resonance Imaging

The EASL diagnostic algorithm for hepatocellular carcinoma, currently in use, dates back to 2018. While awaiting its update, numerous advancements have emerged in the field of hepatocellular carcinoma imaging. These innovations impact every step of the diagnostic algorithm, from surveillance protocols to diagnostic processes, encompassing aspects preceding a patient's inclusion in surveillance programs as well as the potential applications of imaging after the hepatocellular carcinoma diagnosis. Notably, these diagnostic advancements are particularly evident in the domain of magnetic resonance imaging. For example, the sensitivity of ultrasound in diagnosing very early-stage and early-stage hepatocellular carcinoma during the surveillance phase is very low (less than 50%) and a potential improvement in this sensitivity value could be achieved by using abbreviated protocols in magnetic resonance imaging. The aim of this review is to explore the 2024 updates in magnetic resonance imaging for hepatocellular carcinoma, with a focus on its role in surveillance, nodular size assessment, post-diagnosis imaging applications, and its potential role before the initiation of surveillance.

Magnetic Resonance Imaging Liver Segmentation Protocol Enables More Consistent and Robust Annotations, Paving the Way for Advanced Computer-Assisted Analysis

BACKGROUND/OBJECTIVES

Recent advancements in artificial intelligence (AI) have spurred interest in developing computer-assisted analysis for imaging examinations. However, the lack of high-quality datasets remains a significant bottleneck. Labeling instructions are critical for improving dataset quality but are often lacking. This study aimed to establish a liver MRI segmentation protocol and assess its impact on annotation quality and inter-reader agreement.

METHODS

This retrospective study included 20 patients with chronic liver disease. Manual liver segmentations were performed by a radiologist in training and a radiology technician on T2-weighted imaging (wi) and T1wi at the portal venous phase. Based on the inter-reader discrepancies identified after the first segmentation round, a segmentation protocol was established, guiding the second round of segmentation, resulting in a total of 160 segmentations. The Dice Similarity Coefficient (DSC) assessed inter-reader agreement pre- and post-protocol, with a Wilcoxon signed-rank test for per-volume analysis and an Aligned-Rank Transform (ART) for repeated measures analyses of variance (ANOVA) for per-slice analysis. Slice selection at extreme cranial or caudal liver positions was evaluated using the McNemar test.

RESULTS

The per-volume DSC significantly increased after protocol implementation for both T2wi (p < 0.001) and T1wi (p = 0.03). Per-slice DSC also improved significantly for both T2wi and T1wi (p < 0.001). The protocol reduced the number of liver segmentations with a non-annotated slice on T1wi (p = 0.04), but the change was not significant on T2wi (p = 0.16).

CONCLUSIONS

Establishing a liver MRI segmentation protocol improves annotation robustness and reproducibility, paving the way for advanced computer-assisted analysis. Moreover, segmentation protocols could be extended to other organs and lesions and incorporated into guidelines, thereby expanding the potential applications of AI in daily clinical practice.

Abbreviated magnetic resonance imaging in hepatocellular carcinoma surveillance: A review

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies of the liver and a leading cause for cancer-related deaths worldwide. HCC surveillance aims at early detection. The recommended strategy for screening HCC is biannual ultrasound with or without alpha-fetoprotein. However, this strategy is associated with sub-optimal sensitivity. Abbreviated magnetic resonance imaging (AMRI) is a promising alternative to ultrasound (US) for surveillance of HCC. The data regarding the role of AMRI in HCC screening is evolving. There are different AMRI protocols, each having its merits and disadvantages. In this review, we discuss the need for AMRI, protocols of AMRI and hindrances to widespread adoption of AMRI.

New strategy of LI-RADS v2018 to improve the sensitivity for small hepatocellular carcinoma ≤ 3.0 cm on extracellular-contrast enhanced MRI

INTRODUCTION

We aimed to modify LI-RADS version 2018 to improve sensitivity and determine the value of the combination of high alpha-fetoprotein (AFP) levels for small HCC (sHCC, ≤ 30 mm) diagnosis.

METHODS

A total of 984 patients at high risk for HCC, with 1204 observations (including 997 small observations ≤ 30 mm), who underwent extracellular contrast-enhanced MRI were enrolled from five independent centers. Blinded readers evaluated the LI-RADS features and categorized each observation according to the LI-RADS v2018, modified LI-RADS and EASL. Odds ratios of LI-RADS major features (MFs) and several high AFP levels for sHCC diagnosis were analyzed using multivariable logistic regression. The modified LR-5 criteria was developed by including no APHE at any size with two MFs, and non-rim APHE with one MF (≥ 10 mm) or with two MFs (< 10 mm). The diagnostic performance of each version of the LR-5 was compared using generalized estimating equations.

RESULTS

APHE, washout, enhancing capsule and five high AFP levels were independently associated with sHCC. In three datasets, the modified LI-RADS had higher sensitivities for sHCC (76.8 ∼ 85.5 % vs. 73.7 ∼ 75.9 %, P < 0.05) to the LR-5 v2018. The modified LI-RADS with AFP ≥ 200 ng/mL as an additional feature or as an alternative to threshold growth provided higher sensitivities for sHCC than LI-RADS v2018 (82.1 ∼ 90.1 % vs. 73.7 ∼ 75.9 %, all P < 0.05), modified LI-RADS (82.1 ∼ 90.1 % vs. 76.8 ∼ 85.5 %, all P < 0.05) and EASL version 2018 (82.1 ∼ 90.1 % vs. 73.3 ∼ 74.7 %, all P < 0.05), with comparable specificities (all P > 0.05).

CONCLUSION

The new strategy of LI-RADS v2018 provides significantly higher sensitivity and comparable specificity than those of LI-RADS v2018 for sHCC diagnosis on ECA-MRI.

MRI for hepatocellular carcinoma and the role of abbreviated MRI for surveillance of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) constitutes the majority of liver cancers and significantly impacts global cancer mortality. While ultrasound (US) with or without alpha-fetoprotein is the mainstay for HCC surveillance, its limitations highlight the necessity for more effective surveillance tools. Therefore, this review explores evolving imaging modalities and abbreviated magnetic resonance imaging (MRI) (AMRI) protocols as promising alternatives, addressing challenges in HCC surveillance.

AREAS COVERED

This comprehensive review delves into the evaluation and challenges of HCC surveillance tools, focusing on non-contrast abbreviated MRI (NC-AMRI) and contrast-enhanced abbreviated MRI protocols. It covers the implementation of AMRI for HCC surveillance, patient preferences, adherence, and strategies for optimizing cost-effectiveness. Additionally, the article provides insights into prospects for HCC surveillance by summarizing meta-analyses, prospective studies, and ongoing clinical trials evaluating AMRI protocols.

EXPERT OPINION

The opinions underscore the transformative impact of AMRI on HCC surveillance, especially in overcoming US limitations. Promising results from NC-AMRI protocols indicate its potential for high-risk patient surveillance, though prospective studies in true surveillance settings are essential for validation. Future research should prioritize risk-stratified AMRI protocols and address cost-effectiveness for broader clinical implementation, alongside comparative analyses with US for optimal surveillance strategies.

Abbreviated MRI for Hepatocellular Carcinoma Surveillance - A Systematic Review and Meta-analysis

BACKGROUND

Given the limited sensitivity of ultrasound in hepatocellular carcinoma (HCC) surveillance, this systematic review and meta-analysis were aimed to assess the diagnostic performance of non-contrast abbreviated MRI (NC-aMRI) compared to contrast-enhanced abbreviated MRI (CE-aMRI) for HCC surveillance, offering evidence-based guidance for clinical decision-making.

METHODS

A comprehensive search was conducted across five databases, identifying studies on aMRI for HCC surveillance. The pooled sensitivity and specificity were estimated using a random effects model. Subgroup analyses and meta-regression were performed by study location, proportion of patients with cirrhosis and HCC, and underlying liver diseases.

RESULTS

The meta-analysis included 27 studies (2009-2023), distributed between Western (n = 14) and Eastern (n = 13) countries. The pooled sensitivity and specificity (95%CI, I2) were 86% (83-88%, 63%) and 92% (90%-94%, 74%). The NC-aMRI protocols reported in 21 studies exhibited 83% (79-87%, 63%) sensitivity and 91% (88-93%, 67%) specificity, while the 15 studies on CE-aMRI protocols displayed 88% (84-91%, 64%) sensitivity and 94% (90-96%, 78%) specificity, with no statistically significant differences in sensitivity (p = 0.078) or specificity (p = 0.157). Subgroup analysis in NC-aMRI studies showed significant differences in sensitivity for high-prevalent chronic hepatitis B (87% vs. 78%, p = 0.003) and studies done in eastern countries (86% vs. 76%, p = 0.018). Additionally, specificity showed significant differences for high-prevalent chronic hepatitis C (94% vs. 90%, p = 0.009), with meta-regression identifying major sources of study heterogeneity as the inclusion of a majority of patients with chronic hepatitis B (p = 0.008) and the geographic regions where studies were conducted (p = 0.030).

CONCLUSION

Surveillance aMRI protocols exhibit satisfactory performance for detecting HCC. NC-aMRI may be used effectively for HCC surveillance, especially in chronic hepatitis B prevalent settings.

Whole-body magnetic resonance imaging at 0.05 Tesla

Despite a half-century of advancements, global magnetic resonance imaging (MRI) accessibility remains limited and uneven, hindering its full potential in health care. Initially, MRI development focused on low fields around 0.05 Tesla, but progress halted after the introduction of the 1.5 Tesla whole-body superconducting scanner in 1983. Using a permanent 0.05 Tesla magnet and deep learning for electromagnetic interference elimination, we developed a whole-body scanner that operates using a standard wall power outlet and without radiofrequency and magnetic shielding. We demonstrated its wide-ranging applicability for imaging various anatomical structures. Furthermore, we developed three-dimensional deep learning reconstruction to boost image quality by harnessing extensive high-field MRI data. These advances pave the way for affordable deep learning-powered ultra-low-field MRI scanners, addressing unmet clinical needs in diverse health care settings worldwide.

Diagnostic Performance of Abbreviated MRI for HCC Detection in Patients with Non-alcoholic Fatty Liver Disease

BACKGROUND/AIM

Hepatocellular carcinoma (HCC) surveillance is recommended in nonalcoholic fatty liver disease (NAFLD)-related cirrhosis. The performance of ultrasound (US) is impaired in NAFLD. This study aimed to evaluate the diagnostic performance of non-contrast abbreviated magnetic resonance imaging (AMRI) for HCC detection in NAFLD.

METHODS

Consecutive contrast-enhanced magnetic resonance imaging (CE-MRI) scans of NAFLD patients between June 2017 and December 2021 were retrieved. A radiologist extracted and anonymized a noncontrast AMRI dataset comprising T2-weighted, T1-weighted, and diffusion-weighted imaging (DWI) sequences. Two radiologists blinded to CE-MRI reports and treatment details independently reviewed the AMRI for liver lesion and portal vein (PV) characteristics. HCC and malignant PV thrombosis were diagnosed based on the original dynamic CE-MRI diagnostic reports. The diagnostic performance of AMRI and the interobserver agreement for detecting HCC and malignant PV thrombosis were calculated.

RESULTS

Seventy-five patients (52 males; mean age (±SD), 56 ± 17.6 years; 61 cirrhotic) were included. Nine patients had HCC (14 HCCs). The sensitivity, specificity, positive predictive value, and negative predictive value of AMRI for detecting HCC were 100%, 93.9%, 69.2%, and 100%, respectively, and malignant PV thrombosis was 100%, 98.5%, 80%, and 100%, respectively. There was substantial interobserver agreement for detecting HCC (kappa = 0.721) and malignant PV thrombosis (kappa = 0.645) on AMRI.

CONCLUSION

AMRI has high diagnostic performance in HCC detection in patients with NAFLD. However, prospective studies must compare the diagnostic performance of AMRI with that of US.